The high importance of the availability of end user computing systems raises the need for effective and efficient helpdesk systems. However, research shows that the adoption and diffusion of such systems is surprisingly low. Classical approaches to deal with this problem solely focus on the system itself, especially by focusing on the quality of the helpdesk. But this neglects the fact, that problem solving often takes place in unofficial personal networks. This aspect gains importance due to the increasing relevance of team-based work structures. Motivated by this, we present a model of adoption of helpdesk system that considers the quality of personal networks as influencing factor for the level of adoption.